Mining Books To Map Emotions Through A Century

When anthropologists tallied the use of emotional words through a century of literature, they included many books without clear emotional content — technical manuals, for example, and automotive repair guides.

Were people happier in the 1950s than they are today? Or were they more frustrated, repressed and sad?

To find out, you'd have to compare the emotions of one generation to another. British anthropologists think they may have found the answer — embedded in literature.

Several years ago, more or less on a lark, a group of researchers from England used a computer program to analyze the emotional content of books from every year of the 20th century — close to a billion words in millions of books.

This effort began simply with lists of "emotion" words: 146 different words that connote anger; 92 words for fear; 224 for joy; 115 for sadness; 30 for disgust; and 41 words for surprise. All were from standardized word lists used in linguistic research.

The original idea was to have the computer program track the use of these words over time. The researchers wanted to see if certain words, at certain moments, became more popular.

But Alex Bentley, an anthropologist at the University of Bristol involved in the research, says no one expected much when they set their computers to search through one hundred years of books that had been digitized by Google.

"We didn't really expect to find anything," he says. "We were just curious. We really expected the use of emotion words to be constant through time."

Instead, in the study they published in the journal PLOS ONE, the anthropologists found very distinct peaks and valleys, Bently says. "The clarity of some of the patterns was surprising to all of us, I think."

With the graphs spread out in front of him, Bentley says, the patterns are easy to see. "The '20s were the highest peak of joy-related words that we see," he says. "They really were roaring."

But then came 1941, which, of course, marked the beginning of America's entry into World War II. It doesn't take a historian to see that peaks and valleys like these roughly mirror the major economic and social events of the century.

"In 1941, sadness is at its peak," Bentley says.

He found that interesting because the books the computers searched in the Google database included an incredibly wide range of topics. They weren't just novels or books about current events, Bentley says. Many were books without clear emotional content — technical manuals about plants and animals, for example, or automotive repair guides.

"It's not like the change in emotion is because people are writing about the Depression and people are writing about the war," he says. "There might be a little bit of that, but this is just, kind of, averaged over all books, and it's just kind of creeping in."

Which brings us to the most surprising finding of the study: We think of modern culture — and often ourselves — as more emotionally open than people in the past. We live in a world of reality television and blogs and Facebook — it feels like feelings are everywhere, displayed to a degree that they never were before. But according to this research, that's not so.

"Generally speaking, the usage of these commonly known emotion words has been in decline over the 20th century," Bentley says. We used words that expressed our emotions less in the year 2000 than we did 100 years earlier — words about sadness and joy and anger and disgust and surprise.

In fact, there is only one exception that Bentley and his colleagues found: fear. "The fear-related words start to increase just before the 1980s," he says.

So what does this tell us? Should we trust it? Could it be that our own sense of ourselves, and how emotionally open we are, is somehow wrong? Bentley says he has no explanation. "We were just so surprised at this result that we just wanted to publish it to show people," he says. "It's such a fascinating thing; I'm excited just to hear other people's interpretations of this data."

"Certainly the general strategy is a really promising way for us to think about emotions in history," says James Pennebaker, a psychologist at the University of Texas, Austin, who has also done language studies on big databases like this. But such analyses are complicated, he says, and it may still be "a little early to know" whether the use of emotional words has actually declined.

For psychologists, he says, there are only a handful of ways to try to understand what is actually going on with somebody emotionally.

"One is what a person says," Pennebaker explains, "kind of the 'self report' of emotion. Another might be the physiological links, and the third is what slips out when they're talking to other people, when they're writing a book or something like that."

For years, psychologists like Pennebaker have worried that self report does not always accurately reflect what's going on with someone, and physiological measures are hard to get.

That's why this language analysis seems so promising to him — as a new window that might offer a different, maybe even more objective, view into our culture. Because, he says, it's difficult for people today to guess the emotions of people of different times.

"Our current emotional state completely biases our memories of the past and our expectations for the future," Pennebaker says. "And, using these language samples, we are able to peg how people are feeling over time. That's what I love about it as a historical marker, so we can get a sense of how groups of people — or entire cultures — might have felt 10 years ago, or 100 years ago."

It's a kind of emotional archaeology, from traces left behind by words.

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Transcript

AUDIE CORNISH, HOST:

It's ALL THINGS CONSIDERED from NPR News. I'm Audie Cornish.

ROBERT SIEGEL, HOST:

And I'm Robert Siegel.

Were people happier in the 1950s than they are today? Or were they more frustrated, repressed, more sad? Is it even possible to compare the emotions of one generation to another? Well, a recently published study may offer a few answers. A group of researchers used a computer program to analyze the emotional content of books from every year of the 20th century, billions of words in millions of books.

NPR's Alix Spiegel reports on one of the strange findings this process produced.

ALIX SPIEGEL, BYLINE: There are so many words for sad.

ALEX BENTLEY: Weepy, grievous, hangdog, shame-faced...

SPIEGEL: And apparently even more for joyful.

BENTLEY: Gusto, relish, glee, zest...

SPIEGEL: Alex Bentley, the man that you hear speaking, is an anthropologist at the University of Bristol. And several years ago, he and some colleagues got interested in words that convey emotion. They wanted to track the use of the words over time, and see if certain words at certain moments became more popular.

BENTLEY: Panic, terror, hysteria, horror...

SPIEGEL: This was 2010 and Google had been digitizing books for several years. In fact, at that point, Google had digitized about 4 percent of all the books ever published. So Bentley and his co-authors turned to a database Google had created to allow researchers like them to search all these books that they had digitized, and sent their computers hurdling through time.

Bentley said they did this more or less on a lark.

BENTLEY: We didn't really expect to find anything. We were just curious. But the clarity of some of the patterns was surprising to all of us, I think.

SPIEGEL: Bentley says the computer analyzed six categories of emotion - sadness, joy, anger, disgust, surprise and fear. And when the researchers began, they expected the use of words describing these emotions to be more or less constant. Instead, they found very distinct peaks and valleys. With a graph spread out in front of him, Bentley says it is easy to see.

BENTLEY: The '20s were the highest peak of joy-related words that we see. So they were roaring.

SPIEGEL: But then, there's 1941.

BENTLEY: Nineteen forty-one, sadness is at its peak.

SPIEGEL: '41, of course, marks the beginning of America's entry into Second World War. And it doesn't take a historian to see that peaks and valleys like these roughly mirror the major economic and social events of the century. Which Bentley found interesting, because the books in the database are on an incredibly wide range of topics. They're not just novels or writing about current events. Many are books without clear emotional content - technical manuals about plants and animals, automotive repair guides.

BENTLEY: It's not like the change in emotion is because people are writing about the Depression and people are writing about the war. It might be a little bit of that, but this is like averaged over all books and it's just kind of creeping in.

SPIEGEL: Which brings us to the most surprising finding of the study. We think of modern culture, and often ourselves, as more emotionally open than people in the past. We live in a world of reality television and blogs and Facebook. It feels like feelings are everywhere, displayed in these ways that they never were before. But according to this research, that's not so.

BENTLEY: Generally speaking, the usage of these commonly known emotion words has been in decline over the 20th century.

SPIEGEL: In other words, we used words that expressed our emotions less in the year 2000 than we did 100 years earlier. Words like...

BENTLEY: Blue, dark, depressing.

SPIEGEL: Or...

BENTLEY: Glee, gusto, relish.

SPIEGEL: These words, Bentley says, have been slowly but surely declining. You can see it on the graphs.

BENTLEY: Joyless.

SPIEGEL: In fact, there is only one exception that Bentley and his colleagues found.

BENTLEY: Fear.

SPIEGEL: Fear increased steadily up until the year 2000 when the study ends.

BENTLEY: The fear-related words start to increase just before the 1980s.

SPIEGEL: So what does this tell us? Should we trust it? Could it be that our own sense of ourselves, and how emotionally open we are is somehow wrong? Bentley says he, frankly, does not know why it would be that books include fewer emotional words today than they did 100 years ago.

BENTLEY: We were just so surprised at this result that we just wanted to publish it to show people. And we don't in the paper have an answer for everything, particularly the decline in emotion-related words through time. But it's just such a fascinating thing. I'm excited just to hear other people's interpretations of this data.

JAMES PENNEBAKER: The general strategy is a really promising way for us to think about emotions in history.

SPIEGEL: This is James Pennebaker, a psychologist at the University of Texas, who also has done language studies on big databases like this. And Pennebaker says he is uncertain about this conclusion that the use of emotional content words has decreased over time.

PENNEBAKER: I think it's a little early to know.

SPIEGEL: This is one of the first studies that's tried to analyze emotional words in this way, he says. And this kind of analyses is very complicated. Still, Pennebaker believes that this method of mining vast amounts of written language, like books, is incredibly promising. For psychologists, he says there are only a handful of ways to try to understand what is actually going on with somebody emotionally.

PENNEBAKER: One is what a person says, kind of the self-report of emotion. Another might be the physiological links, and the third is what slips out when they're talking to other people, when they're writing a book or something like that.

SPIEGEL: For years, psychologists like Pennebaker have worried that self-report does not always accurately reflect what's going on with someone, and physiological measures are hard to get; which is why this language analysis seems promising to him - a new window which might offer a different, maybe even more objective view into our culture. Because it's difficult for people today to guess the emotions of people of different times.

PENNEBAKER: Our current emotional state completely biases our memories of the past and our expectation for the future. And using these language samples, we are able to peg how people are feeling over time, and that's what I love about it as a historical marker. So we can get a sense of how groups of people - or entire cultures - might have felt 10 years ago, or 100 years ago.